TW201536700A - Method for cutting brittle material substrate - Google Patents

Abstract

This invention aims to inhibit damages of blade edge for cutting brittle material substrate and substrate surface. In this invention, a cutting edge 51 is pressed against a brittle material substrate 4 so that a protruding part PP of the cutting edge 51 is arranged between a first edge ED1 of the brittle material substrate 4 and the side part PS of the cutting edge 51 and so that the side part PS of the cutting edge 51 is arranged between the protruding part PP of the cutting edge 51 and a second edge ED2 of the brittle material substrate 4. A scribe line is formed by scratching on the brittle material substrate 4 between a first position closer to the first edge ED1 of the first and second edges ED1, ED2 and a second position closer to the second edge ED2 of the first and second edges ED1, ED2. After the scribe line has been formed, a crack line is formed by extending a crack in the direction of thickness DT from the second position to the first position along the scribe line.

Description

Method for breaking brittle material substrate

The present invention relates to a method of breaking a substrate of a brittle material.

In the manufacture of an electric device such as a flat display panel or a solar cell panel, it is often necessary to separate a brittle material substrate such as a glass substrate. In a typical breaking method, a slit (hereinafter referred to as a crack line) that extends at least partially in the thickness direction of the substrate is formed in a line shape on the surface of the substrate by a scribing device.

According to Japanese Laid-Open Patent Publication No. Hei 9-188534 (Patent Document 1), some dents on the surface of the glass plate are glass defects which are generated when scribing, and this is called a scribe line. Further, according to the above publication, a slit extending from the scribe line in the downward direction is generated simultaneously with the scribe line. That is, a crack line is formed while forming a scribe line.

When the crack completely travels in the thickness direction, the substrate can be broken along the crack line as long as the crack line is formed. On the other hand, when the crack only partially travels in the thickness direction, after the crack line is formed, stress imparting is referred to as a breaking step. The substrate is separated by causing the crack of the crack line to completely travel in the thickness direction by the breaking process. If the crack line is not formed, the breaking along the substrate of the scribe line cannot be performed even if the stress is applied in the breaking step. Therefore, in order to reliably separate the glass sheets, it is necessary to form the crack lines surely.

Further, in order to form a crack line, it is necessary to have a crack which becomes the starting point (hereinafter referred to as a starting crack). The starting crack can be simply formed by the tip of the blade across the edge of the substrate. This is because the edge of the substrate is liable to cause local damage. By sliding the blade tip over the surface of the glass substrate, the crack line can be extended from the starting crack. However, the tip of the knife is straddle The action of the edge of the substrate results in a large damage to the tip or a large defect in the edge of the substrate. Therefore, in most cases, it is desirable to completely avoid such actions or to suppress their frequency.

As a method of forming the starting crack, there is also a method of not depending on the edge of the blade across the edge of the substrate. For example, Japanese Patent Laying-Open No. 2000-264656 (Patent Document 2) discloses a scribing device including a scribing body having a milling cutter and a vibration generating member that imparts vibration to the milling cutter. According to this method, the milling cutter is positioned directly above the starting point of the scribing by relatively moving the scribing body along the surface of the workpiece in a state of being spaced apart from the workpiece. Then, by lowering the scribing body, the tip end of the milling cutter abuts against the starting point of the scribing line due to the weight of the scribing body. Thereafter, by applying an impact to the scribe line body, a starting point crack is formed at a starting point of the scribe line spaced apart from the edge of the workpiece. By imparting vibration to the workpiece, the starting line crack can be used as a trigger to form a scribe line.

[Previous Technical Literature] [Patent Literature

[Patent Document 1] Japanese Patent Laid-Open Publication No. Hei 9-188534

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2000-264656

In order to form the crack line, it is necessary to adjust the shape of the scribing tool, the scribing load, the speed, and the like in consideration of various types and thicknesses of the glass plate. In recent years, with the development of thinner, higher-strength glass, it has become increasingly difficult to form crack lines. For example, in order to form a true crack line, if the scribing load is increased, the wear of the blade tip is increased, and the damage generated on the glass surface is increased to generate more dust. Also, it is difficult to speed up the scribing speed. In this way, the conditions of the scribing or the use of the tip are relatively narrow. Further, there is a slanting of the surface of the glass plate or the surface of the glass plate facing the glass plate, and the scribe line is formed in the thickness direction of the glass plate. As a result, the glass end surface after the division is inclined.

Further, according to the scribing device described in the above publication, the scribing body is provided The impact forms a crack at the starting point. However, when the starting point of the scribing is to be obtained depending only on the impact, a large impact must be applied to the milling cutter. Therefore, a large damage is applied to the tip of the milling cutter, and the surface of the substrate at the starting point of the scribing is also slightly damaged.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a brittle material substrate which can be formed along a scribe line after forming a scribe line and which can suppress damage to the blade edge and the substrate surface. Break method.

The breaking method of the brittle material substrate of the present invention comprises the following steps.

A brittle material substrate having a surface surrounded by edges including the first and second sides facing each other and having a thickness direction perpendicular to the surface is prepared.

The tip is pressed against the surface of the brittle material substrate. The blade tip has a protrusion and a side portion that extends from the protrusion and has a convex shape. The pressing of the blade edge is performed by arranging a protrusion of the blade edge between the first side and the side portion on the surface of the brittle material substrate, and arranging the side portion of the blade edge between the protrusion portion and the second side.

The blade tip pressed by the pressing of the blade edge slides on the surface of the brittle material substrate, thereby approaching the first position of the first side in the first and second sides on the surface of the brittle material substrate And a groove-shaped scribe line is formed between the first and second sides of the first and second sides.

After the scribing is formed, the crack of the brittle material substrate in the thickness direction is extended from the second position to the first position along the scribe line, thereby forming a crack line.

The brittle material substrate is broken along the crack line.

According to the present invention, after the scribing is formed, the crack line can be formed along the scribe line. Since it is not necessary to simultaneously generate the crack line and the scribing line, it is easy to select the cutting edge or the scribing condition, and the scribing speed can be increased. Moreover, it is hard to be affected by the unevenness of the surface of the substrate or the mounting table, so that the end surface quality of the brittle material after the breaking is stable and improved. Furthermore, since the tip and substrate table can be suppressed The damage of the surface can extend the life of the blade tip and increase the strength of the substrate after the break.

4‧‧‧ glass substrate

50‧‧‧ cutting instruments

51‧‧‧Tool tip

51v‧‧‧ pointed

52‧‧‧Knife

AL‧‧‧Auxiliary line

AX‧‧‧ axis direction

CL‧‧‧ crack line

DA‧‧‧ directions

DB‧‧‧ direction

DT‧‧‧ thickness direction

ED1‧‧‧ side (1st side)

ED2‧‧‧ side (2nd side)

ED3‧‧‧ side (3rd side)

ED4‧‧‧ side (4th side)

IB‧‧ arrow

N1‧‧‧ position (1st position)

N2‧‧‧ position (2nd position)

N3‧‧‧ position

N4‧‧‧ position

PP‧‧‧Protruding

PPv‧‧‧Protruding

PS‧‧‧ side

PSv‧‧‧ side

SC‧‧‧Conical surface

SD1‧‧‧ top surface (1st side)

SD2‧‧‧ side (2nd side)

SD3‧‧‧ side (3rd side)

SF‧‧‧ surface

SL‧‧‧

S10~S50‧‧‧Steps

Fig. 1 is a side view (A) showing a configuration of an apparatus for use in a glass substrate breaking method according to a first embodiment of the present invention, and a blade having the above-described apparatus schematically showing an arrow IB viewpoint of Fig. 1 (A). Top view of the configuration of the tip (B).

Fig. 2 is a cross-sectional view (A) showing a configuration of a scribe line formed in the glass substrate breaking method according to the first embodiment of the present invention, and a cross-sectional view (B) schematically showing the configuration of the rupture line.

Fig. 3 is a flow chart schematically showing the configuration of a glass substrate breaking method according to the first embodiment of the present invention.

Fig. 4 is a plan view schematically showing a first step of the glass substrate dividing method according to the first embodiment of the present invention.

Fig. 5 is a plan view schematically showing a second step of the glass substrate dividing method according to the first embodiment of the present invention.

FIG. 6 is a plan view schematically showing a first step of the glass substrate breaking method according to the first modification of the first embodiment of the present invention.

FIG. 7 is a plan view schematically showing a second step of the glass substrate breaking method according to the first modification of the first embodiment of the present invention.

FIG. 8 is a plan view schematically showing one step of a method of dividing a glass substrate according to a second modification of the first embodiment of the present invention.

FIG. 9 is a plan view schematically showing one step of a method of dividing a glass substrate according to a third modification of the first embodiment of the present invention.

Fig. 10 is a plan view schematically showing a first step of the glass substrate dividing method according to the second embodiment of the present invention.

Fig. 11 is a plan view schematically showing a second step of the glass substrate dividing method according to the second embodiment of the present invention.

Fig. 12 is a plan view schematically showing a third step of the glass substrate dividing method according to the second embodiment of the present invention.

Fig. 13 is a plan view schematically showing one step of a method of dividing a glass substrate according to a first modification of the second embodiment of the present invention.

FIG. 14 is a plan view schematically showing a first step of the glass substrate breaking method according to the second modification of the second embodiment of the present invention.

Fig. 15 is a plan view showing a second step of the glass substrate dividing method according to a second modification of the second embodiment of the present invention.

Fig. 16 is a plan view schematically showing one step of a method of dividing a glass substrate according to a third modification of the second embodiment of the present invention.

Fig. 17 is a plan view schematically showing a step of a method of dividing a glass substrate according to a third embodiment of the present invention.

Fig. 18 is a plan view schematically showing a first step of the glass substrate dividing method according to the fourth embodiment of the present invention.

Fig. 19 is a plan view schematically showing a second step of the glass substrate dividing method according to the fourth embodiment of the present invention.

Fig. 20 is a plan view schematically showing a first step of the glass substrate dividing method according to the fifth embodiment of the present invention.

Fig. 21 is a plan view schematically showing a second step of the glass substrate dividing method according to the fifth embodiment of the present invention.

Fig. 22 is a plan view schematically showing one step of the glass substrate breaking method in the fifth embodiment of the present invention.

Fig. 23 is a side view (A) showing a configuration of an apparatus for use in a glass substrate breaking method according to a sixth embodiment of the present invention, and a knife having the above-described apparatus which schematically shows an arrow IB viewpoint of Fig. 1 (A). Top view of the configuration of the tip (B).

Hereinafter, embodiments of the present invention will be described based on the drawings. In the following, the same or corresponding components are denoted by the same reference numerals, and the description thereof will not be repeated.

(Embodiment 1)

In the present embodiment, a glass substrate is used as the brittle material substrate. Examples of the brittle material substrate include a ceramic substrate including a low-temperature fired ceramic or a high-temperature fired ceramic, a tantalum substrate, a compound semiconductor substrate, a sapphire substrate, and a quartz substrate.

Referring to Fig. 1 (A) and (B), a cutting tool 50 is used for the method of dividing the glass substrate of the present embodiment. The cutting tool 50 includes a blade tip 51 and a shank 52. The tip 51 is held by a shank 52 as its holder.

The cutting edge 51 is provided with a top surface SD1 (first surface) and a plurality of surfaces surrounding the top surface SD1. The plurality of faces include a side surface SD2 (second surface) and a side surface SD3 (third surface). The top surface SD1, the side surfaces SD2, and the SD3 (the first to third surfaces) are oriented in mutually different directions and adjacent to each other. The blade tip 51 has a vertex at which the top surface SD1, the side surfaces SD2, and SD3 meet, and the apex constitutes the protrusion PP of the blade edge 51. Further, the side faces SD2 and SD3 are ridge lines constituting the side portions PS of the blade edge 51. The side portion PS extends linearly from the protrusion portion PP. Moreover, since the side portion PS is a ridge line as described above, it has a convex shape extending linearly.

The tip 51 is preferably a diamond tip. That is, the cutting edge 51 is preferably made of diamond in terms of reduction in hardness and surface roughness. More preferably, the tip 51 is made of single crystal diamond. Further preferably, from the crystallographic point of view, the top surface SD1 is a {001} plane, and the side surfaces SD2 and SD3 are each a {111} plane. In this case, the side faces SD2 and SD3 have different orientations, but are crystallographically equivalent to each other.

Further, non-single crystal diamond may be used. For example, a polycrystalline diamond synthesized by a CVD (Chemical Vapor Deposition) method may be used. Alternatively, a sintered diamond obtained by combining polycrystalline diamond particles sintered from particulate graphite or non-graphite carbon without a bonding material such as an iron group element, and a bonding material such as an iron group element may be used.

The shank 52 extends along the axial direction AX, and the cutting edge 51 is preferably at the normal of the top surface SD1. The shank 52 is attached to the axial direction AX.

Further, referring to FIG. 2(A), in order to form the scribe line SL using the dicing tool 50, the protrusion portion PP and the side portion PS of the blade edge 51 are pressed against the thickness direction DT of the glass substrate 4 on the surface SF of the glass substrate 4. Next, the blade edge 51 is slid on the surface substantially in the direction in which the side portion PS is projected onto the surface SF. Thereby, a groove-shaped scribe line which does not accompany a vertical crack is formed on the surface SF. Although the groove-shaped scribe line can be produced by at least either plastic deformation or cutting of the glass substrate 4, it is preferably formed by plastic deformation in order to avoid generation of fine glass fragments due to cutting.

Further, referring to FIG. 2(B), there are cases where the scribe line SL and the crease line CL are simultaneously formed by the sliding of the blade edge 51, and the scribe line SL is formed. The crack line CL is a slit extending from the dent of the scribe line SL in the thickness direction DT, and extends linearly on the surface SF. According to the method described later, after only the scribe line SL is formed, the crack line CL can be formed along it.

Referring to FIG. 3, the method of breaking the glass substrate 4 mainly includes steps S10 to S50. The details will be described below.

Referring to Fig. 4, in step S10 (Fig. 3), the glass substrate 4 is first prepared. The glass substrate 4 has a flat surface SF surrounded by edges including ED1 (first side) and side ED2 (second side) facing each other. The glass substrate has a thickness direction DT perpendicular to the surface SF (Figs. 1 and 2). In the example shown in Fig. 4, the edges are rectangular. Therefore, the sides ED1 and ED2 are parallel to each other. Moreover, in the example shown in FIG. 4, the sides ED1 and ED2 are the short sides of the rectangle.

In step S20 (FIG. 3), the blade edge 51 is pressed against the position N1 on the surface SF of the glass substrate 4. The details of the position N1 will be described later. The pressing of the cutting edge 51 is performed as follows with reference to Fig. 1 in which the projection PP of the cutting edge 51 is disposed between the side ED1 and the side portion PS on the surface SF of the glass substrate 4, and is disposed between the projection PP and the side ED2. The side portion PS of the cutting edge 51.

In step S30 (FIG. 3), a plurality of scribe lines SL (five lines in the drawing) are formed on the surface SF of the glass substrate 4. The formation of the scribe line SL is performed between the position N1 (first position) and the position N3. A position N2 (second position) is located between the positions N1 and N2. Therefore, the scribe line SL is formed in Between the positions N1 and N2 and between the positions N2 and N3. The positions N1, N2 and N3 are spaced apart from the edge of the surface SF of the glass substrate 4. Therefore, the formed scribe line SL is spaced apart from the edge of the glass substrate 4. The position N1 is closer to the side ED1 in the sides ED1 and ED2. The position N2 is closer to the side ED2 in the side ED1 and the side ED2. The scribe line SL is formed by scratches caused by sliding the blade edge 51 pressed against the surface SF of the glass substrate 4 on the surface SF.

In the case where the scribe line SL is formed, in the present embodiment, the blade edge 51 is displaced from the position N1 to the position N2, and is displaced from the position N2 to the position N3. That is, referring to Fig. 1, the blade edge 51 is displaced from the side ED1 toward the side ED2, that is, toward the direction DA. The direction DA corresponds to a direction in which the axis AX extending from the blade edge 51 is projected on the surface SF. In this case, the blade tip 51 is dragged on the surface SF by the shank 52.

Referring to FIG. 5, in step S40 (FIG. 3), after the scribe line SL is formed, the crack of the glass substrate 4 in the thickness direction DT (FIG. 2(B)) is along the scribe line SL from the position N2 to the position N1 ( In the figure, it is stretched with reference to a broken line arrow to form a crack line CL. The crack line CL is started to be formed by the auxiliary line AL and the scribe line SL crossing each other at the position N2. For this purpose, the auxiliary line AL is formed after the scribe line SL is formed. The auxiliary line AL is a type of crack line (Fig. 2(B)) formed by a crack in the thickness direction DT of the glass substrate 4.

The method of forming the auxiliary line AL is not particularly limited, but as shown in FIG. 4, the edge of the surface SF can be formed as a base point. In this case, in order to form the auxiliary line AL, there is a need to move the blade edge 51 over the edge of the surface SF of the glass substrate 4, but since the number of the auxiliary lines AL is generally one, which is smaller than the number of the scribe lines SL, Therefore, the impact caused by this action is small.

Further, it is more difficult to form the crack line CL from the position N2 toward the position N3 than in the direction from the position N2 to the position N1. That is, the ease of stretching of the crack line CL has a direction dependency. Therefore, a phenomenon occurs in which the crack line CL is formed between the positions N1 and N2 and is not formed between the positions N2 and N3. In the present embodiment, the glass substrate 4 between the positions N1 and N2 is broken, and the glass substrate 4 between the positions N2 and N3 is not broken. Therefore, it is necessary to form the crack line CL between the position N1 and the position N2, but at the position N2. The difficulty of forming the crack line CL between the positions N3 does not become a problem.

In step S50 (Fig. 3), the glass substrate 4 is separated along the crack line CL. Specifically, the breaking process is performed. Further, when the crack line CL completely travels in the thickness direction DT at the time of its formation, the formation of the crack line CL and the breaking of the glass substrate 4 can be simultaneously performed. In this case, the breaking process can be omitted.

The division of the glass substrate 4 is performed by the above.

Referring to Fig. 6, the first variation is a case where the timing of the formation of the crack line CL (Fig. 5) by the intersection of the auxiliary line AL and the scribe line SL is insufficient. Referring to Fig. 7, the glass substrate 4 is separated along the auxiliary line AL by applying stress to the glass substrate 4. Thereby, the crack line CL starts to form. Further, in FIG. 6, the auxiliary line AL is formed on the surface SF of the glass substrate 4, but the auxiliary line AL for separating the glass substrate 4 may be formed on the back surface (the surface opposite to the surface SF) of the glass substrate 4. In this case, the auxiliary line AL and the scribe line SL are in a planar layout, and although they intersect each other at the position N2, they are not in direct contact with each other.

Referring to Fig. 8, in the second modification, in step S20 (Fig. 3), the blade edge 51 is pressed against the position N3 on the surface SF of the glass substrate 4. In step S30 (FIG. 3), when the scribe line SL is formed, in the present modification, the blade edge 51 is displaced from the position N3 to the position N2, and further displaced from the position N2 to the position N1. That is, referring to Fig. 1, the blade edge 51 is displaced from the side ED2 toward the side ED1, that is, toward the direction DB. The direction DB corresponds to a direction opposite to a direction in which the axis AX extending from the blade edge 51 is projected on the surface SF. In this case, the tool tip 51 is advanced on the surface SF by the shank 52.

Referring to Fig. 9, in the third modification, in step S30 (Fig. 3), when the scribe line SL is formed, the blade tip is pressed with a greater force at the position N2 than the position N1 of the surface SF of the glass substrate 4. 51. Specifically, the position N4 is set as the position between the positions N1 and N2, and when the formation of the scribe line SL reaches the position N4, the load of the blade edge 51 is increased. In other words, the load of the scribe line SL is increased between the positions N4 and N3 which are the end portions of the scribe line SL as compared with the position N1. Thereby, it is easier to induce the crack line CL to start from the position N2 by reducing the load other than the terminal portion. to make.

(Embodiment 2)

Referring to Fig. 10, in the present embodiment, the auxiliary line AL is formed before the scribe line SL is formed. The method of forming the auxiliary line AL is the same as that of Fig. 5 (Embodiment 1).

Referring to Fig. 11, next to step S30 (Fig. 3), a scribe line SL is formed. The method of forming the scribe line SL is the same as that of Fig. 4 (Embodiment 1). The auxiliary line AL and the scribe line SL are intersected at the position N2.

Referring to Fig. 12, the glass substrate 4 is separated along the auxiliary line AL by applying stress to the glass substrate 4. Thereby, the crack line CL which is the same as that of the first embodiment is started to be formed (in the drawing, the dotted arrow is referred to). Further, in FIG. 10, the auxiliary line AL is formed on the surface SF of the glass substrate 4, but the auxiliary line AL for separating the glass substrate 4 may be formed on the back surface (the surface opposite to the surface SF) of the glass substrate 4. In this case, the auxiliary line AL and the scribe line SL intersect each other at the position N2 in the plane layout, but do not directly contact each other.

The configuration other than the above is substantially the same as the configuration of the first embodiment.

Referring to Fig. 13, in the first modification, the auxiliary line AL and the scribe line SL intersect each other at the position N2, and the crack line CL is formed.

Referring to Fig. 14, in the second modification, as in Fig. 8 (Embodiment 1), the scribe line SL is formed from the position N3 to the position N1. Referring to Fig. 15, the glass substrate 4 is separated along the auxiliary line AL by applying stress to the glass substrate 4. Thereby, the crack line CL starts to form (in the figure, the dotted arrow is referred to).

Referring to Fig. 16, in the third modification, in step S30 (Fig. 3), at the time of forming the scribe line SL, the blade edge 51 is pressed at a position N2 by a force greater than the position N1 on the surface SF of the glass substrate 4. Specifically, the position N4 is set as the position between the positions N1 and N2, and when the scribe line SL is formed to the position N4, the load of the blade edge 51 is increased. In other words, the load of the scribe line SL is increased between the positions N4 and N3 which are the end portions of the scribe line SL as compared with the position N1. Thereby, it is possible to more easily induce the formation of the crack line CL from the position N2 by reducing the load other than the end portion.

(Embodiment 3)

Referring to Fig. 17, in the present embodiment, in step S30 (Fig. 3), the scribe line SL is formed as follows.

The blade tip 51 is slid over the edge ED2 from the position N1. When the blade edge 51 passes the side ED2, the stress deformation generated inside the substrate directly under the scribe line is released, and the crack line is extended from the end of the scribe line SL on the side ED2 toward the position N1 (FIG. 3: step S40).

The load applied to the cutting edge 51 when the scribing line SL is formed may be constant, but the load applied to the cutting edge 51 may be increased at the position N2 when the cutting edge 51 is displaced from the position N1 to the position N2. For example, the load is increased by about 50%. The blade tip 51 to which the increased load is applied is slid over the side ED2. In other words, the load of the blade edge 51 is increased at the end portion of the scribe line SL. When the cutting edge 51 reaches the side ED2, the crack line extends from the end of the scribe line SL on the side ED2 to the position N1 via the position N2 (FIG. 3: step S40). When the load is increased in this manner, since the stress deformation also increases, the stress is easily released when the blade edge 51 passes through the side ED2, so that the crack line can be surely formed.

The configuration other than the above is substantially the same as the configuration of the first embodiment.

(Embodiment 4)

Referring to Fig. 18, in the present embodiment, in step S30 (Fig. 3), a scribe line SL from the position N1 to the side ED2 via the position N2 is formed.

Referring to Fig. 19, a stress is then applied between the position N2 and the side ED2. Thereby, the induced crack line is formed along the scribe line SL (FIG. 3: step S40).

Specifically, as the application of the stress, between the position N2 on the surface SF and the side ED2 (the area between the broken line and the side ED2 in the drawing), the pressed blade edge 51 is slid. This sliding proceeds until reaching the edge ED2. The blade edge 51 preferably slides so as to intersect the track of the first formed scribe line SL, and more preferably slides over the track of the first formed scribe line SL. The length of the re-sliding is, for example, about 0.5 mm. Moreover, the re-sliding system may be performed on each of the plurality of scribe lines SL (FIG. 18), or may be performed on each of the scribe lines SL. The process of forming one scribe line SL and performing the sliding again is performed.

As a modification, in order to apply a stress between the position N2 and the side ED2, instead of the above-described blade 51 being slid again, laser light may be irradiated on the surface SF between the position N2 and the side ED2. The crack line can also be induced to form by the thermal stress thus generated.

The configuration other than the above is substantially the same as the configuration of the first embodiment.

(Embodiment 5)

Referring to Fig. 20, in the present embodiment, in step S30 (Fig. 3), the cutting edge 51 is displaced from the position N1 to the position N2 and then to the position N3, thereby forming a scribe line SL spaced apart from the edge of the surface SF. . The method of forming the scribe line SL is substantially the same as that of FIG. 4 (Embodiment 1).

Referring to Fig. 21, the same stress application as in Fig. 19 (Embodiment 4 or a modification thereof) is performed. Thereby, the crack line is induced to be formed along the scribe line SL (FIG. 3: step S40).

Referring to Fig. 22, as a variation of the process of Fig. 20, in the formation of the scribe line SL, the blade edge 51 may be displaced from the position N3 to the position N2 and then from the position N2 to the position N1.

The configuration other than the above is substantially the same as the configuration of the above-described first embodiment.

(Embodiment 6)

Referring to Fig. 23, in each of the above embodiments, the blade edge 51v may be used instead of the blade edge 51 (Figs. 1(A) and (B)). The blade tip 51v has a conical shape including a vertex and a conical surface SC. The protrusion PPv of the blade edge 51v is constituted by a vertex. The side portion PSv of the blade edge is formed along a virtual line (dashed line in Fig. 23(B)) extending from the apex toward the conical surface SC. Thereby, the side portion PSv has a convex shape that extends linearly.

Further, in each of the above embodiments, the first and second sides of the edge of the glass substrate are short sides of a rectangle, but the first and second sides may be long sides of a rectangle. Further, the shape of the edge is not limited to a rectangle, and may be, for example, a square. Further, the first and second sides are not limited to a straight line, and may be curved. Further, in each of the above embodiments, the surface of the glass substrate is a flat surface, but the surface may be curved.

The present invention can freely combine various embodiments within the scope of the invention, or appropriately change The embodiments are omitted.

4‧‧‧ glass substrate

50‧‧‧ cutting instruments

51‧‧‧Tool tip

52‧‧‧Knife

AX‧‧‧ axis direction

DA‧‧‧ directions

DB‧‧‧ direction

DT‧‧‧ thickness direction

ED1‧‧‧ side (1st side)

ED2‧‧‧ side (2nd side)

IB‧‧ arrow

PP‧‧‧Protruding

PS‧‧‧ side

SD1‧‧‧ top surface (1st side)

SD2‧‧‧ side (2nd side)

SD3‧‧‧ side (3rd side)

SF‧‧‧ surface

Claims (10)

A method for breaking a substrate of a brittle material, comprising: a step of preparing a substrate of a brittle material having a surface surrounded by edges including first and second sides facing each other, and having a thickness perpendicular to the surface a step of pressing the blade edge against the surface of the brittle material substrate, the blade edge including a protrusion portion and a side portion extending from the protrusion portion and having a convex shape, wherein the pressing step is performed as follows The protrusion on the surface of the brittle material substrate is disposed between the first side and the side portion, and the side portion of the blade edge is disposed between the protrusion and the second side; The method for dividing the brittle material substrate includes: sliding the blade edge pressed by the pressing step on the surface of the brittle material substrate, thereby forming the first surface on the surface of the brittle material substrate a step of forming a groove-shaped scribe line between the first side of the second side adjacent to the first side and the second position of the first and second sides adjacent to the second side After the step of forming the scribe line, the step of forming the crack line by extending the crack of the brittle material substrate in the thickness direction from the second position to the first position along the scribe line; The crack line divides the step of the above-mentioned brittle material substrate. The breaking method of the brittle material substrate according to claim 1, wherein the cutting edge includes: first to third faces adjacent to each other, a vertex of the first to third faces meeting, and the second and third faces The ridge line is formed by the apex of the blade tip, and the side portion of the blade edge is formed by the ridge line. A method for breaking a substrate of a brittle material according to claim 1, wherein The cutting edge has a conical shape including a vertex and a conical surface, and the protrusion of the cutting edge is formed by the vertex, and the side of the cutting edge is along a virtual line extending from the vertex toward the conical surface. Composition. The method for dividing a brittle material substrate according to any one of claims 1 to 3, wherein the step of forming the scribing step includes a step of displacing the blade tip from the first position to the second position. The method for dividing a brittle material substrate according to any one of claims 1 to 3, wherein the step of forming the scribing step includes a step of displacing the blade tip from the second position to the first position. The method for dividing a brittle material substrate according to any one of claims 1 to 3, wherein the step of forming the scribing is performed by forming a scribe line spaced apart from the edge; and further comprising the step of forming an auxiliary line The auxiliary line is formed by a crack of the brittle material substrate in the thickness direction, and the auxiliary line and the scribing line intersect each other at the second position. The breaking method of the brittle material substrate according to claim 6, wherein the step of forming the crack line is started by the auxiliary line and the scribing line intersecting each other at the second position. The breaking method of the brittle material substrate according to claim 6, wherein the step of forming the crack line is started by separating the brittle material substrate along the auxiliary line by applying stress to the brittle material substrate. The method for dividing a brittle material substrate according to any one of claims 1 to 3, wherein the step of forming the scribing step includes a step of sliding the blade tip from the first position beyond the second side. The method for breaking a brittle material substrate according to any one of claims 1 to 3, wherein the step of forming the crack line comprises: applying a stress between the second position and the second side after the step of forming the scribing line Process.